Fix initStripe load order, subscription webhook email extraction, chat textarea UX

- checkout.el: swap stripe_el_script before auth_script so initStripe is
  defined when Supabase auth fires onAuthStateChange on page load
- main.el: fix Stripe webhook email extraction for checkout.session.completed
  (subscription) events — customer_details is nested at data.object level,
  not at root; previous code only worked for payment_intent.succeeded
- page_close.c: replace <input type="text"> with <textarea rows="1"> in
  the chat widget input row so long questions are visible as you type
- page_css.c: update #neuron-demo-text CSS for textarea (resize:none,
  overflow:hidden, min/max-height, align-items:flex-end on row)
- chat-widget.el: add auto-resize event listener (grows up to ~4 lines),
  reset height to auto on send

dist/page_css.c

@@ -1764,6 +1764,7 @@ el_val_t page_css(void) {
         "\n"
         "    #neuron-demo-input-row {\n"
         "      display: flex;\n"
+        "      align-items: flex-end;\n"
         "      border-top: 1px solid var(--border);\n"
         "      flex-shrink: 0;\n"
         "    }\n"
@@ -1771,11 +1772,16 @@ el_val_t page_css(void) {
         "      flex: 1;\n"
         "      font-family: var(--body);\n"
         "      font-size: 0.875rem;\n"
+        "      line-height: 1.5;\n"
         "      color: var(--t1);\n"
         "      background: var(--bg);\n"
         "      border: none;\n"
         "      outline: none;\n"
         "      padding: 0.875rem 1rem;\n"
+        "      resize: none;\n"
+        "      overflow: hidden;\n"
+        "      min-height: 2.75rem;\n"
+        "      max-height: 7.5rem;\n"
         "    }\n"
         "    #neuron-demo-text::placeholder { color: var(--t3); }\n"
         "    #neuron-demo-send {\n"

src/checkout.el

@@ -341,7 +341,7 @@ fn checkout_page(plan: String, pub_key: String) -> String {
     let stripe_el_script: String = el_script_src("/js/checkout-stripe.js", true)
     let free_init_script: String = ""
 
-    return nav_html + main_html + supabase_script + stripe_script + style_html + auth_script + cfg_script + stripe_el_script + free_init_script
+    return nav_html + main_html + supabase_script + stripe_script + style_html + stripe_el_script + cfg_script + auth_script + free_init_script
 }
 
 fn checkout_style_html() -> String {

src/js/chat-widget.el

@@ -497,6 +497,7 @@ fn main() -> Void {
       return;
     }
     input.value = '';
+    input.style.height = 'auto';
     btn.disabled = true;
     addMsg('user', msg);
 
@@ -617,6 +618,10 @@ fn main() -> Void {
     inp.addEventListener('keydown', function(e) {
       if (e.key === 'Enter' && !e.shiftKey) { e.preventDefault(); window.neuronDemoSend(); }
     });
+    inp.addEventListener('input', function() {
+      this.style.height = 'auto';
+      this.style.height = Math.min(this.scrollHeight, 120) + 'px';
+    });
   }
 })()")
 }

src/main.el

@@ -1548,13 +1548,20 @@ fn handle_request_inner(method: String, path: String, headers: Map, body: String
 
         if is_session_done || is_pi_done || is_si_done {
             // Pull email/name/customer_id - fields differ slightly across event
-            // types, walk a few candidates.
+            // types. Walk several candidates:
+            //   receipt_email           - PaymentIntent (founding one-time)
+            //   data.object.*           - full dot-path for checkout.session.completed (subscription)
+            //   customer_details.email  - substring fallback if nested key appears at any level
+            //   billing_details.email   - Elements payment intents
             let customer_email: String = json_get(body, "receipt_email")
+            if str_eq(customer_email, "") { let customer_email = json_get(body, "data.object.customer_details.email") }
             if str_eq(customer_email, "") { let customer_email = json_get(body, "customer_details.email") }
             if str_eq(customer_email, "") { let customer_email = json_get(body, "billing_details.email") }
-            let customer_name: String = json_get(body, "customer_details.name")
+            let customer_name: String = json_get(body, "data.object.customer_details.name")
+            if str_eq(customer_name, "") { let customer_name = json_get(body, "customer_details.name") }
             if str_eq(customer_name, "") { let customer_name = json_get(body, "billing_details.name") }
-            let customer_id: String = json_get(body, "customer")
+            let customer_id: String = json_get(body, "data.object.customer")
+            if str_eq(customer_id, "") { let customer_id = json_get(body, "customer") }
 
             // Plan inference from metadata
             let plan: String = "free"